Model sailing boat



Nov. 14, 1961 KOHNSTAM 3,008,268

MODEL SAILING BOAT Filed April 11, 1960 sail 14 is fitted in the conventional manner.

United States Patent 3,008,268 MODEL SAILING BOAT Richard Kohnstarn, Trevellance Lewins Road, Gerrards Cross, England FiledApr. 11, 1960, Ser. No. 21,445 Claims priority, application Great Britain Apr. 27, 1959 2 Claims. (Cl. 46243) This invention relates to an improved model sailing boat and has for its object to provide therein an auxiliary motor which is automatically brought into operation if the model is becalmed.

One of the disadvantages of model sailing boats is that once they have been released to sail on a certain course, they are no longer within the control of the operator and if, in the course of the voyage, the wind should drop the model remains motionless far from the shore. In many instances it has been necessary either to wade or row out on to the stretch of water to recover the model or to abandon it.

According to the said invention, a model sailing boat is provided with an auxiliary motor and propeller driven thereby, means for stopping and starting the motor, and means whereby the swinging movement of the models boom actuates the said stoppingancl starting means.

In one embodiment of the said invention the motor is provided with control means biasing it to the on position, and means are provided coupling the boom of the model to the control means arranged so that when the boom is moved to one side or the other by the force of the wind the control means is pulled to the OE position, but when the model is becalmed the motor is set in motion by the centralising of the boom.

The motor may be a clockwork motor, the control means being coupled to the starting and stopping mechanism thereof. Alternatively the motor may be an electric motor, a battery being provided in the hull of the model, and the control means is coupled to a switch. In either case the control means may consist of a lever movable about a fulcrum and urged to a central position by opposing springs.

Adjusting means may be provided by which the amplitude of boom movement required to pull the control means to the oli" position may be adjusted.

To promote a clear understanding of the invention one example thereof will now be described with reference to the drawings accompanying this specification, but it is to be understood that the invention is not limited to this embodiment.

In the said drawings:

FIGURE 1 is a side elevation of a part of a model sailing boat;

FIGURE 2 is a plan view of the boat shown in FIG- URE l; and

FIGURE 3 is a diagrammatic view of the control arrangement.

Referring to the drawings, and initially to FIGURE 1, a model sailing boat comprises a hull 11 having a main mast 12 which supports, at an appropriate height, a boom 13 swingably mounted thereon so as to move from a centralised position corresponding to the longitudinal centre of the model to port and starboard. A When the model is sailing the boom is pulled to one side or the other by the force of the wind and the amount of movement permitted is controlled by the main sheet 15, which is a cord secured at one end to the boom 13 and which passes through an eye 16 anchored to the deck of the model, to a further eye 17 secured to the main mast and has its other end fixed to an adjusting device 18 to enable the length of the sheet to be adjusted. The boom is shown in one of the extreme positions in FIGURE 2.

Patented Nov. 14, 1%61 In accordance with the invention, a small motor 29 (shown in FIGURE 3) is mounted inside the hull of the model and a propeller 19 coupled to the motor projects from the rear of the hull. The motor could be a clockwork type with a start-stop mechanism or it may be en electric motor, as shown, powered by a battery within the hull of the model and controlled by aswitch.

The eye 16 is fitted to the top of a lever 20 (see FIGURE 3) which is movable about a fulcrum 21 intermediate of its length to the extent permitted by two stops 22 and 23 secured to the fixed structure. The fulcrum 21 is on any part of the relatively fixed structure of the model. The lever 20 oscillates in a vertical plane and is urged towards its central position by a pair of opposing springs 24 and 25 one end of each of which is attached to the lever 20, the other ends of the springs being anchored to the fixed structure. The direction of movement of the eye 16 about the fulcrum 21 is shown by the double headed arrow in FIGURE 2.

In its central position the lower end of the lever 20 makes contact with a spring contact 26. A battery 27 feeds the motor and is electrically connected to the lever 20 and the contact 26 is connected to one terminal of the motor 29, the other terminal of the motor being connected to the other pole of the battery 27. The circuit is completed through a switch comprising contact between the lever 20 and the contact 26; the motor 29 runs to drive the propeller 19.

When there is wind available the boom is moved to one side or the other by the force of the wind acting upon the sail 14, to the extent permitted by the sheet 15. This causes a sideways pull on the eye 16 which moves the lever 20 in one direction or the other to break the electric circuit, so that the model sails in the ordinary way under the influence of the Should the wind drop so that the model is becalmed the springs 24 and 25 bring the lever 20 back to the central position thus making the contact between the lever 20 and the contact 26 so that the motor runs and the model continues its journey under power.

An auxiliary switch may be fitted to switch off the motor when the model is not in use.

It will be understood that if the motor is of the clockwork type the lever 20 may be connected to the startstop mechanism thereof.

In a modification, the main sheet is deflected downwards from the mast so as to engage a part of a switch prior to continuing via a deck eye to the boom. This engagement may be by passing through a hole or slot in the switch part, or under a hooked part thereof. As with the previous case the switch is biassed to the On position but is maintained in the Off when the main sheet is taut.

In another way of carrying out the invention the boom is provided with a springy wiping contact in the battery-and-motor circuit so that the said contact sweeps over the deck as the boom swings from side to side, and in the arcuate path of this wiping contact, there is fixed to the deck, on the longitudinal centre thereof, a metal plate forming a complemental contact. The two contacts constitute a switch for the motor which is on when the boom is centralised but off when the boom moves oif centre under the influence of the wind.

I claim:

1. A model sailing boat having an auxiliary electric motor, a battery energizing said motor and a propeller driven thereby, a boom swingably mounted on the mast of the model, a sail carried by said boom, said boom and sail being subject to movement by wind impinging on said sail, means controlling the circuit from the battery to the motor, said means including a switch, a lever pivoted intermediate its length to a fixed structure so 'as to oscillate in a vertical plane, means connecting the upper end of said lever to said boom, said means comprising a main sheet passing through, an eye on the upper end of said lever end having its opposite ends connected to a fixed anchorage, the lower end of said lever r r 4 the boom and engagement of the lower end of the lever with the switch.

2. A model sailing boat according to claim 1 in which the main sheet is provided with means to adjust the em- 5 plitude of movement of the boom.

operating said switch, and a pair of opposing springs secured to said lever and nrging it, to a central on position, whereby movement of said boom to one side zbjeealmedo the motor is set in motion by centralizing of References Cited in the file of this patent UNITED STATES PATENTS Wentworth July 24, 1951 7 OTHER REFERENCES American Modeler, November 1949, pgs. 27 and 40. 

